Glycerol is a byproduct of biodiesel production and of other fine chemical syntheses, such as those of perfumes, fragrances, and pharmaceuticals.1 Currently the biodiesel industry in the United States produces 2.0 billion gallons of glycerol each year,2 with an increase projected in the future.3 Because glycerol constitutes about 10% of the weight of crude biodiesel, the utilization of this “waste” is an opportunity for new technology.4 Significant effort has been invested in catalytic conversion of glycerol to value-added products.5 Selective dehydrogenation of glycerol to lactic acid is particularly appealing, because lactic acid is both a valuable feedstock for organic synthesis and a precursor for poly(lactic acid) (PLA), a biodegradable polymer. The market demand of PLA is estimated at 150,000 metric tons by 2017 and 400,000 metric tons by 2022.6 Moreover, when such conversions are conducted by acceptorless dehydrogenation, the byproduct H2 is a readily separable, energy carrier that has value as such. In these regards, homogeneous conversion of glycerol to lactic acid has shown promising reactivity and good selectivity.7 
Accordingly, there is a need for efficient processes for efficiently converting glycerol to lactic acid, and in particular, poly(lactic acid),